Cadillac Tech Tips - How to fix it Discussion, How To Clean The EGR Valve in Item Specific Cadillac Discussion; I recently purchased a 95 sts with 85,000 miles on it. Shortly after I got it, I noticed a wierd ...

How To Clean The EGR Valve

I recently purchased a 95 sts with 85,000 miles on it. Shortly after I got it, I noticed a wierd problem under light acceleration(around 1700 to 2300 rpms from a standstill). The acceleration is not steady. You can feel it and also watch the needle jump up and down slightly on the tach. What could be causing this and what should I do. I bought a warranty that covers drivetrain and engine stuff for 3 months or 3,000 miles and I am hoping to fix this under the warranty. Admittedly it is not that big of a deal, but it is annoying and I am wondering if performance could be better.

Re: 95 sts acceleration problem

Sounds like a sticky EGR valve to me. Just give me a sec to copy and paste another post of mine here to help you...

here it is:

How to clean a sticky EGR valve

This article pertains to all models with the OBD-I Northstar 4.6L V8.

The symptoms of a sticky EGR valve are surging while trying to keep the throttle steady (not to be confused with surging at idle), and
code P036 (E036). Although it is possible to have a sticky valve with no code (that's how mine was).

First of all, don't do this job when the engine is hot. You WILL burn yourself. Your first task is finding the Exhaust Gas Recirculation (EGR) valve.
It is located underneath the spark plug wire cover near the rear bank of the engine. You will have to move the spark plug wire cover, you
don't have to completely take it off. Just lift it up and lay it sideways on top of the engine.

Now you need to unbolt the EGR valve. To do this, you will need a ratchet with an extension, and a 10mm socket.
Once you know the bolts are unscrewed all the way, don't try to remove them. Instead remove the whole EGR valve with the bolts still in the holes.
This will prevent you from dropping and loosing the bolts.

On the bottom of the valve you will see two holes, one that is plugged with what appears to be a screw and one that is open.
The screw like object is the valve. You should be able to press it in easily and when you let it go, it should close itself again (it's spring loaded).
The one I was working with was sticking in the closed position.

To clean the valve, simply spray carborator cleaner on and in the valve and wipe the dirt off with a cloth. Be very careful not to get it into
the canister, as the carb cleaner is a very powerful deturgent that will eat away the insulation on the windings in the sensor.
The following picture shows what you should not do.

The picture below on the other hand shows the right way.

Once you're all done cleaning the valve, you can reuse the gasket and put it all back together. Just make sure that when you put the
spark plug wire cover back into place that it clears the water pump belt.

What you have just done, should take care of your P036 (also E036) code. You can go into diagnostics mode and clear the code. If by chance it
didn't take care of the code (the code comes back after clearing it and going for a test drive), repeat the process.
If you can't get the code to go away, no matter how many times you clean the valve, replace the valve.

Re: How To Clean The EGR Valve

Great Tip! The same process works on '96 and newer obd-II cars, you just have to move the fuel lines out of the way to get the EGR out. And the code on my '96 SLS was P1406. Thanks for the tips! Oh, its also a good idea to clean the carbon deposit out of the EGR supply and outlet tubes on the engine.

Re: How To Clean The EGR Valve

Great post and pictures..!

I know this sounds like a noob question...it actually IS a noob question, but I'm new with Caddys and car mechanics in general...so please bear with me....um....how exactly do you check for codes?? I have a 96 STS

Re: How To Clean The EGR Valve

It may be risky, but I do not see a problem with putting the egr valve in a pan of carb cleaner. Just make sure the level of carb cleaner does not go higher than the valve stem where the rubber boot is. It probably isn't good for the gasket though. However, when I remove my egr valve, the gasket stays on the engine. In Krashed's pics, his gasket is still on the valve.

Re: How To Clean The EGR Valve

I've been watching this thread for awhile and the whole time I've wondered just how much could this part cost to justify all the work to clean it. Wow, was I surprised! $200 at the parts store alone, how much would it be at the dealer? I now have a copy of this cleaning procedure folded neatly into my factory service manual! Thanks!
lrry99eldo